# Al2.7Ir: enthalpy of formation

> Enthalpy of formation of Al2.7Ir: 5 literature value(s) with sources, pages and quotes, from ORCHID.

HTML: https://data.orchid-project.org/compounds/Al2.7Ir.html · Markdown: https://data.orchid-project.org/compounds/Al2.7Ir.md

5 accepted literature formation-enthalpy value(s) (model 4, DFT 1).

Systems: [Al–Ir](https://data.orchid-project.org/systems/AL-IR.html)

## Literature values

Table: Enthalpy of formation of Al2.7Ir reported in the literature (5)

| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---:|---|---:|---|---|---|---|---|---|
| -69.7 kJ/mol-atom | Al2.7Ir | 0 | model |  | [Al–Ir](https://data.orchid-project.org/systems/AL-IR.html) | [1] JIANG 2006 | Table 4, p. 4, row 3; `ORC-EP63T5JKQK.48f132` |  |
| -68.8 kJ/mol-atom | Al2.7Ir | 0 | model |  | [Al–Ir](https://data.orchid-project.org/systems/AL-IR.html) | [1] JIANG 2006 | Table 4, p. 4, row 6; `ORC-4F7X5PYCOO.64e7cc` |  |
| -68.3 kJ/mol-atom ± 0.5 | Al2.7Ir | 0 | model |  | [Al–Ir](https://data.orchid-project.org/systems/AL-IR.html) | [1] JIANG 2006 | Table 4, p. 4, row 6; `ORC-4F7X5PYCOO.8552a1` |  |
| -67.8 kJ/mol-atom | Al2.7Ir | 0 | model |  | [Al–Ir](https://data.orchid-project.org/systems/AL-IR.html) | [1] JIANG 2006 | Table 4, p. 4, row 6; `ORC-4F7X5PYCOO.5769a4` |  |
| -68.3 kJ/mol-atom | Al2.7Ir |  | DFT |  | [Al–Ir](https://data.orchid-project.org/systems/AL-IR.html) | [2] Abe 2008; _cites Jiang 2006_ | Table 2, p. 3, row 16; `ORC-IFIJC3VV2P.5646ae` |  |

### Uncertainty budget

Components kept separate, in the value's unit (literature [SCHEMA.md](https://data.orchid-project.org/literature/SCHEMA.md), [UNCERTAINTY_CALIBRATION.md](https://data.orchid-project.org/literature/UNCERTAINTY_CALIBRATION.md)): effective = max(sqrt(max(printed, reading, method)^2 + composition^2 + conversion^2), scatter). The method floor is the robust between-study scatter of the method class in ORCHID (calibrated) or a documented prior; printed values and printed uncertainties are unchanged.

Table: Uncertainty budget of the literature values of Al2.7Ir

| Value | Unit | Printed | Reading | Method (class, basis) | Composition | Scatter | Conversion | Effective |
|---:|---|---:|---:|---|---:|---:|---:|---:|
| -69.7 | kJ/mol-atom |  | 0.05 | 3.9 (model_calculated, calibrated) |  |  |  | 3.9 |
| -68.8 | kJ/mol-atom |  | 0.05 | 3.9 (model_calculated, calibrated) |  |  |  | 3.9 |
| -68.3 | kJ/mol-atom | 0.5 | 0.05 | 3.9 (model_calculated, calibrated) |  |  |  | 3.9 |
| -67.8 | kJ/mol-atom |  | 0.05 | 3.9 (model_calculated, calibrated) |  |  |  | 3.9 |
| -68.3 | kJ/mol-atom |  | 0.05 | 8.395 (dft, calibrated) |  |  |  | 8.395 |

## Sources

1. C JIANG, B GLEESON, A combined first-principles/CALPHAD modeling of the Al–Ir system, Acta Materialia 54, 4101-4110 (2006). [doi:10.1016/j.actamat.2006.03.058](https://doi.org/10.1016/j.actamat.2006.03.058)
2. T. Abe, C. Kocer, M. Ode, H. Murakami, Y. Yamabe-Mitarai, K. Hashimoto et al., Thermodynamic re-assessment of the Al–Ir system, Calphad 32, 686-692 (2008). [doi:10.1016/j.calphad.2008.09.014](https://doi.org/10.1016/j.calphad.2008.09.014)

## Please cite

- R. Arróyave, J. Saal, D. Shin, ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/10.5281/zenodo.23735569
- R. Arróyave, J. Saal, D. Shin, ORCHID-Parity: DFT-vs-experiment formation-enthalpy benchmark (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/10.5281/zenodo.23735943
- R. Arróyave, J. Saal, D. Shin, ORCHID data: umbrella record of the ORCHID datasets (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/10.5281/zenodo.23736065

Also cite the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work); A. Jain et al., The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1 (2013) 011002, https://doi.org/10.1063/1.4812323 (CC BY 4.0); J. E. Saal et al., JOM 65 (2013) 1501, https://doi.org/10.1007/s11837-013-0755-4 and S. Kirklin et al., npj Comput. Mater. 1 (2015) 15010, https://doi.org/10.1038/npjcompumats.2015.10 (CC BY 4.0); G. Kim, S. V. Meschel, P. Nash, W. Chen, Experimental formation enthalpies for intermetallic phases and other inorganic compounds, Scientific Data 4 (2017) 170162, https://doi.org/10.1038/sdata.2017.162; B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, https://doi.org/10.1016/j.calphad.2025.102833 (CC BY 4.0), and the original assessment named in each file.

Version 1, machine-extracted: values were read by language-model readers constrained to quote their source and checked automatically, and the release was then audited on the printed pages by adversarial audits, an independent second review of fit-facing records and a preliminary human review of a frozen sample. Flags such as accepted and ESPEI-ready record screening results, not certification; known issues are listed in the release notes.

```bibtex
@misc{orchid_literature_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735569},
  url       = {https://doi.org/10.5281/zenodo.23735569},
  note      = {Version 1, machine-extracted}
}

@misc{orchid_dft_benchmark_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Parity: DFT-vs-experiment formation-enthalpy benchmark}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735943},
  url       = {https://doi.org/10.5281/zenodo.23735943},
  note      = {Version 1, machine-extracted}
}

@misc{orchid_data_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID data: umbrella record of the ORCHID datasets}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23736065},
  url       = {https://doi.org/10.5281/zenodo.23736065},
  note      = {Version 1, machine-extracted}
}
```

---

Derived data CC BY 4.0 ([licence](https://creativecommons.org/licenses/by/4.0/)): cite ORCHID ([CITATION.cff](https://data.orchid-project.org/CITATION.cff)) and the original sources. Quotes are short excerpts kept so that each value can be checked; they remain under the publishers' copyright and are not relicensed. Source papers, page images and full text are not redistributed. Field reference: [SCHEMA.md](https://data.orchid-project.org/literature/SCHEMA.md). Machine-readable guide: [llms.txt](https://data.orchid-project.org/llms.txt). Found an error? The report link of a value (Markdown: its id, ORC-..., in the Location column) opens a pre-filled GitHub issue, https://github.com/orchid-calphad/orchid-data/issues/new?template=report-value-error.yml&record_id=\<id>, carrying only the record id, source and value; [how to contribute](https://orchid-project.org/contribute/).